1. Field of the Invention
The invention relates to a door lock wherein the roller catch comprises in addition to the pre-catch also a main catch into which the pawl drops. Sometimes a gap remains when closing an open door because the pawl reaches only the pre-catch of the roller catch. This means that the roller catch remains in its pre-catch position. In order to be.able to close the gap, the auxiliary motor means are provided which engage the roller catch. They have the task to further move the roller catch into its final position in which the pawl drops into the main catch. In the following, this final position will be referred to as xe2x80x9cmain catch positionxe2x80x9d. The door gap is now closed.
2. Description of the Related Art
In a known door lock (DE 195 33 196 A1) two drive motors cooperate via two gears with a pivotable carousel support on which the pawl is positioned. One motor serves as a closing aid and the other motor as an opening aid. During closing, the pawl is pushed away by a pre-catch interruption lever until, by means of the locking part being inserted, the roller catch has reached its final main catch position relative to the pawl and the pawl drops into the main catch of the roller catch. Only thereafter, the drive motor is started and pivots the carousel support with the pawl so that the pawl rotates the roller catch past the main catch position into its rotational end position. In this case, a pawl that is entrained by the gear is provided, and the roller catch, after the pawl has dropped into its main catch, is still moved farther. An interruption of the drive motor is not provided and thus also does not result in a release of the transmission chain between the motor and the roller catch.
The known door lock requires a lot of space. During closing of the aforementioned door gap disruptions may result, for example, by an obstacle which projects into the door gap. Then it is required that any further movement of the roller catch is immediately interrupted and the pressure of the gear acting on the door is cancelled.
It is an object of the invention to develop a reliable door lock of the kind mentioned in the preamble of claim 1 which, on the one hand, improves the operating comfort but, on the other hand, is of a space-saving configuration. This is achieved according to the invention by one and the same drive motor being used for the closing aid as well as for the opening aid, by a transmission member being arranged in the gear and switchable between two switching positions, by the drive energy exerted by the drive motor reaching the transmission member but, as a function of the switching position of the transmission member, reaching alternatively behind the transmission member the roller catch or the locking pawl via one of two separate drive paths, wherein one drive path belongs to the closing aid and the other belongs to the opening aid.
According to the invention, one and the same drive motor can be used for the closing aid as well as for the opening aid. It is sufficient in this context to arrange in the gear a transmission member which can be controlled to alternate between two switching positions. The drive energy provided by the drive motor is transmitted on a common path to the transmission member. Behind the transmission member, however, the drive energy is alternatively guided on one of two separate drive paths. One drive paths belongs to the closing aid and the other to the opening aid. It depends only on the switching position of the transmission member onto which one of the two drive paths the drive energy is directed. Accordingly, the apparatus expenditure is substantially reduced.
For reversing the transmission member, it is recommended that the transmission member is secured by a spring force normally in that switching position in which the drive energy exerted by the drive motor is not transmitted to the roller catch, that the transmission member is connected with a switching device which, at a defined limit angle of the roller catch and/or of the pawl, is activated and transfers the transmission member into its other switching position wherein the drive energy exerted by the drive motor acts on the roller catch in the pulling shut direction, and that the switching device is deactivated in a disturbance situation during the pulling shut phase as well as in the main catch position and, by doing so, the transmission member is automatically returned by the spring force again into its switched off position. Usually, the transmission member is secured by a spring force in that switching position in which the drive energy of the drive motor does not reach the roller catch. This normal situation is also present in the open position of the roller catch up to a certain limit angle position of the roller catch as well as in the final main catch position. This limit angle position may be, for example, the pre-catch position of the roller catch. Only when the limit angle position of the roller catch during closing of the door has been reached, a switching device is activated which reverses the transmission member. This switching device engages the transmission member and transfers the transmission member into its other position where the drive energy of the drive motor acts on the roller catch and can pull it shut.
In the case of disruption, only the control impulse acting on the switching device must be turned off. Subsequently, the pulling shut phase is simply interrupted in that the switching device releases the transmission member and the latter is returned into its other switching position because of the spring force. Since the remaining gear portion connected to the roller catch is released, the roller catch is no longer arrested and the pressure acting on the door is relieved. Even the effect of the elastic door seals can result in a return movement of the roller catch. After switching of the transmission member has occurred in the pulling shut phase, it may be possible that the drive motor that has been set in motion as well as the drive members, positioned in front of and moved by the transmission member, will move still according to the principle of inertia, but the movement energy of these masses is no longer transmitted onto the roller catch. The roller catch is immediately set still, respectively, it can even rotate in the opposite direction.
Of independent inventive importance is the third embodiment according to which, for determining the respective position of the door, control means are provided which comprise two sensors and a control logic connected to the sensors, wherein one sensor responds to a certain angle position of the roller catch, or a certain position of the locking part of the door post supporting the locking part relative to the lock of the door, respectively, and, subsequently, will be referred to as roller catch sensor, while the other sensor responds to the drop of the pawl into the pre-catch as well as into the main catch of the roller catch and is therefore referred to as pawl sensor, and wherein the control logic evaluates commonly the individual signals coming from the two sensors and the different alternatives described in connection therewith. This door lock can also be used independent of a pulling shut aid and/or an opening aid. However, in individual situations the use in connection with a door lock according to the above described first and second embodiments is possible and will also be explained in the following description in more detail. The door lock according to the third embodiment concerns the following problem.
It is important to determine the respective position of the door unequivocally in order to, according to this determination, initiate further functions of the vehicle or to control them, for example, the interior illumination of the vehicle. For this purpose, sensors are used. In the past it was required to position the sensors within very tight tolerances for an exact position determination of the door. Moreover, the use of correspondingly exactly operating sensors was required. Finally, the high sensitivity of the sensors should not change during their service life. The manufacture of sensors with such high requirements is difficult and expensive. Moreover, the known sensors had to be exactly mounted which is cost-intensive. The invention avoids these disadvantages by special control means. In this connection the following effects result.
Because of the common evaluation of the individual signals of the two sensors, an exact positioning of these sensors with respect to the roller catch or with respect to the pawl is initially not required. Mounting of the sensors is therefore facilitated, faster, and can be performed less expensively. Moreover, the invention makes it possible to even use relatively imprecisely operating sensors because the summation evaluation of the signals allows to determine the respective door position very precisely. According to the invention it is also of no consequence when the sensitivity of the two sensors decreases over the course of time. In this case the summation-based control logic can determine very precisely the point in time.